Method and device for controlling the drive of a magnetic levitation vehicle on a magnetic levitation track

Abstract

A method provides for the traction control of a maglev car on a maglev track. A levitation magnetic field is produced by supplying a levitation magnetic flux on the car side to at least two levitation magnets to produce a defined air gap between the maglev car and a reaction rail on the track side. A stator current is supplied to the stator to produce a propulsion force on the maglev track, the propulsion force acts upon the maglev car being determined by the magnetic coupling between the magnetic stator field and the magnetic levitation field. An oscillating movement of the maglev car in relation to the magnetic stator field is dampened by changing the magnetic coupling between the magnetic stator field and the magnetic levitation field on the car side. The levitation magnets are operated on the car side with at least two different individual levitation magnetic fluxes.

1. A method for controlling a drive of a magnetic levitation vehicle on a magnetic levitation track, which comprises the steps of:
 generating a levitation magnetic field on the magnetic levitation vehicle by respectively feeding in a vehicle-side levitation magnet current into at least two levitation magnets of the magnetic levitation vehicle to bring about a predefined air gap between the magnetic levitation vehicle and a track-side reaction rail; 
 feeding a stator current into a track-side stator of the magnetic levitation track to bring about a propulsion force on the magnetic levitation track, the propulsion force acting on the magnetic levitation vehicle being determined by a magnetic coupling between a stator magnetic field and the levitation magnetic field; and 
 damping an oscillating movement of the magnetic levitation vehicle relative to the stator magnetic field by changing the magnetic coupling between the stator magnetic field and the levitation magnetic field on a vehicle side, by operating the levitation magnets on the vehicle side with at least two individual levitation magnet currents of different sizes; 
 setting a distribution of the current between the levitation magnets such that the predefined air gap between the magnetic levitation vehicle and a reaction rail remains constant independently of a respectively set magnetic coupling; 
 during a predefined special operating mode, feeding in the at least two individual levitation magnet currents of different sizes into the levitation magnets, and a special coupling, which is reduced compared to a maximum possible coupling, between the stator magnetic field and the levitation magnetic field is set, and
 if the magnetic levitation vehicle is moving quicker than the stator magnetic field in a direction of travel, reducing the magnetic coupling by increasing the difference in current in the individual levitation magnet currents; and 
 if the magnetic levitation vehicle is moving slower than the stator magnetic field in the direction of travel, increasing the magnetic coupling by reducing a difference in current in the individual levitation magnet currents. 
 
 
     
     
       2. The method according to  claim 1 , wherein within a scope of a drive control, a change in a pole angle between the stator magnetic field and a magnetic reference axis of the magnetic levitation vehicle is counteracted. 
     
     
       3. The method according to  claim 2 , which further comprises:
 measuring the change in the pole angle over time to form a change variable; and 
 changing the magnetic coupling between the stator magnetic field and the levitation magnetic field in dependence on the change variable. 
 
     
     
       4. The method according to  claim 1 , which further comprises:
 reducing the magnetic coupling if the magnetic levitation vehicle is moving quicker than the stator magnetic field in a direction of travel; and 
 increasing the magnetic coupling if the magnetic levitation vehicle is moving slower than the stator magnetic field in the direction of travel. 
 
     
     
       5. The method according to  claim 1 , which further comprises actuating the levitation magnets in pairs such that a levitation force of a levitation magnet pair respectively remains constant. 
     
     
       6. The method according to  claim 5 , which further comprises forming the levitation magnet pairs such that the levitation magnets of each levitation magnet pair are respectively located directly next to one another. 
     
     
       7. The method according to  claim 5 , which further comprises forming the levitation magnet pairs such that in each case a force transmitting device for transmitting a force between a frame of the magnetic levitation vehicle and the respective levitation magnet pair is located between the levitation magnets of each levitation magnet pair. 
     
     
       8. The method according to  claim 1 , which further comprises controlling the current through the levitation magnets over time such that averaged over time a same current flows through all the levitation magnets. 
     
     
       9. The method according to  claim 1 , which further comprises selecting a set difference in current between the individual levitation magnet currents in a predefined special operating state in dependence on a control effect which is required at a respective time, and the difference in current is set smaller the smaller the respectively required control effect. 
     
     
       10. A magnetic levitation vehicle, comprising:
 levitation magnets; 
 a gap measuring device for measuring an air gap between said levitation magnets and a track-side reaction rail; 
 a control device connected to said gap measuring device and causes a generation of a levitation magnet current for said levitation magnets of the magnetic levitation vehicle, said control device configured such that, in order to damp an oscillating movement of the magnetic levitation vehicle relative to a stator magnetic field, said control device can change a magnetic coupling between the stator magnetic field and the levitation magnetic field by feeding individual levitation magnet currents of different sizes into said levitation magnets; 
 said control device is suitable for dimensioning the individual levitation magnet currents such that a total levitation force of all said levitation magnets of the magnetic levitation vehicle and said air gap between the magnetic levitation vehicle and the track side reaction rail remains constant independently of a respectively set magnetic coupling; 
 said control device:
 in a special operating mode feeds the individual levitation magnet currents of different sizes into said levitation magnets and sets a special coupling, which is reduced compared to a maximum possible coupling, between the stator magnetic field and the levitation magnetic field; 
 if the magnetic levitation vehicle moves quicker than the stator magnetic field in the direction of travel, said control device reduces the magnetic coupling by increasing a difference in the current between the individual levitation magnet currents; and 
 if the magnetic levitation vehicle moves slower than the stator magnetic field in the direction of travel, said control device increases the magnetic coupling by reducing a difference in the current between the individual levitation magnet currents. 
 
 
     
     
       11. The magnetic levitation vehicle according to  claim 10 , wherein said control device is suitable for counteracting a change in a pole angle between the stator magnetic field and a magnetic reference axis of the magnetic levitation vehicle by changing the magnetic coupling. 
     
     
       12. The magnetic levitation vehicle according to  claim 11 , further comprising a pole angle change measuring device for measuring the change in the pole angle over time to form a change variable, said pole angle change measuring device is connected to said control device. 
     
     
       13. The magnetic levitation vehicle according to  claim 12 , wherein said pole angle change measuring device has a pole angle measuring device and a differentiating element. 
     
     
       14. The magnetic levitation vehicle according to  claim 12 , wherein said pole angle change measuring device includes:
 an acceleration sensor for measuring an acceleration of the magnetic levitation vehicle; 
 a difference forming element disposed downstream of said acceleration sensor and forms a difference value between a respective acceleration value of said acceleration sensor and a predefined acceleration value of the stator magnetic field; and 
 an integrating element disposed downstream of said difference forming element. 
 
     
     
       15. The magnetic levitation vehicle according to  claim 12 , wherein said pole angle change measuring device has two induction coils and an evaluation device disposed downstream. 
     
     
       16. The magnetic levitation vehicle according to  claim 10 , wherein said control device:
 reduces the magnetic coupling if the magnetic levitation vehicle is moving quicker than the stator magnetic field in a direction of travel; and 
 increases the magnetic coupling if the magnetic levitation vehicle is moving slower than the stator magnetic field in the direction of travel. 
 
     
     
       17. A magnetic levitation vehicle, comprising:
 levitation magnets; 
 a gap measuring device for measuring an air gap between said levitation magnets and a track-side reaction rail; 
 a control device connected to said gap measuring device and causes a generation of a levitation magnet current for said levitation magnets of the magnetic levitation vehicle, said control device configured such that, in order to damp an oscillating movement of the magnetic levitation vehicle relative to a stator magnetic field, said control device can change a magnetic coupling between the stator magnetic field and the levitation magnetic field by feeding individual levitation magnet currents of different sizes into said levitation magnets; 
 said control device is suitable for dimensioning the individual levitation magnet currents such that a total levitation force of all said levitation magnets of the magnetic levitation vehicle and said air gap between the magnetic levitation vehicle and the track side reaction rail remains constant independently of a respectively set magnetic coupling; and 
 said levitation magnets are respectively actuated in pairs such that a levitation force of each levitation magnet pair remains respectively constant. 
 
     
     
       18. The magnetic levitation vehicle according to  claim 17 , wherein said levitation magnets of each levitation magnet pair are respectively located directly next to one another. 
     
     
       19. The magnetic levitation vehicle according to  claim 17 , further comprising:
 a frame; and 
 force transmitting devices each for transmitting a force between said frame of the magnetic levitation vehicle and each said levitation magnet pair, said force transmitting devices each being located between said levitation magnets of a respective levitation magnet pair. 
 
     
     
       20. The magnetic levitation vehicle according to  claim 19 , wherein at least one of said force transmitting devices of the magnetic levitation vehicle is formed by a spring.